Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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VALVES AND METHODS FOR MANUFACTURING THE VALVES
BACKGROUND OF THE INVENTION
Field of the Invention
1011 The present invention relates to fluid system valves. The invention
concerns, more
particularly, polymeric valves and methods for manufacturing the valves that
limit,
check, or otherwise direct fluid flow within a fluid system.
Description of Background Art
[021 Modern articles of athletic footwear often include two primary elements,
an upper and a
sole structure. The upper comfortably secures the foot to the sole structure
and may be
formed of a combination of materials that are stitched or adhesively bonded
together,
including leather, thermoset foam, and textiles. The sole structure ordinarily
includes
multiple layers that are conventionally referred to as an insole, midsole, and
outsole. The
insole is a thin, padded member located adjacent to the foot that enhances the
comfort of
the footwear. The midsole forms the middle layer of the sole structure and
often includes
a resilient, foam material, such as polyurethane or ethylvinylacetate, that
attenuates
impact forces and absorbs energy when the footwear makes contact with the
ground. The
outsole is usually fashioned from a durable, wear resistant material and
includes texturing
to improve traction.
[031 In addition to a foam material, midsoles may include a fluid system that
relies upon
valves to direct the flow of fluid within the system. Fluid systems may be
used to
achieve a variety of benefits including enhanced cushioning, improved fit, or
ventilation
of the upper. With respect to cushioning fluid systems, U.S. Patent Numbers
5,558,395
and 5,937,462 to Huang disclose fluid systems that utilize ambient air to
pressurize one
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or more bladders that are positioned within the midsole. One-directional
valves, also
referred to as check valves, permit air to enter a pump or inflation system
but prevent, or
check, fluid flow in the opposite direction. U.S. Patent Numbers 4,446,634 to
Johnson et
al. and 5,794,361 to Sadler disclose self-contained fluid systems that include
two
bladders in fluid communication. The bladders are joined by conduits that
include valves
for directing fluid flow. With respect to ventilation, U.S. Patent Number
6,085,444 to
Cho discloses an article of ventilated footwear that includes a series of
bladders and one-
directional valves that draw outside air into the system and then discharge
the air into the
upper, thereby reducing or eliminating the presence of moisture in the area
immediately
surrounding the foot.
[04] The fluid systems discussed above utilize a variety of valve types to
direct fluid flow
within the system. U.S. Patent Numbers 5,144,708 to Pekar and 5,564,143 to
Pekar et al.
disclose one-directional valves formed of two polymer layers attached along
opposite
sides to form a channel between the layers. The valves are manufactured as a
separate
component and then incorporated into a fluid system. Manufacturing of the
valves
includes the use of a barrier material that prevents the valve layers from
being bonded to
each other when the valve is incorporated into a fluid system.
SUMMARY OF THE INVENTION
[05] Some embodiments of the present invention provides a method of
manufacturing valves
suitable for footwear fluid systems. The valves may be manufactured integral
with the fluid
systems, or the valves may be formed as separate components and subsequently
incorporated
into the fluid systems. In accordance with the method, a first sub-assembly is
constructed by
forming a substrate weld between a first valve layer and a first substrate
layer, the first
valve layer having an inlet end and an opposite outlet end. The first sub-
assembly is then
aligned with a second element such that the first valve layer is positioned
between the
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first substrate layer and the second element. Finally, the first valve layer
is bonded with
the second element by forming a pair of spaced channel welds between the first
valve
layer and the second element. The channel welds define a channel located
between the
first valve layer and the second element and between the channel welds. The
channel has
an inlet adjacent to the inlet end of the valve layer and an opposite outlet
adjacent to the
outlet end of the valve layer.
[06] The valves that are formed in accordance with this method are primarily
one-directional
valves, also referred to as check valves. One end of the channel forms an
inlet for the
valve and an opposite end forms an outlet. Fluid may enter the valve by
flowing into the
inlet. Fluid then progresses through the channel and exits the valve by
passing through
the outlet. Fluid flow in the opposite direction is restricted by the
configuration of the
channel outlet. The inlet may include two weld beads that place the inlet in
an open
configuration, thereby facilitating the entry of fluid. The outlet may have a
variety of
geometries, including an opening between the valve layer and the second
element or an
aperture formed in the valve layer.
[07] In forming the first sub-assembly, the first valve layer is bonded to the
first substrate
layer such that the first valve layer is properly positioned on the first
substrate layer
during subsequent steps of the method. A first weld flow director is utilized
to prevent a
weld bead from forming adjacent to at least a portion of the bond area. When
bonding
the first valve layer to the second element, a second weld flow director is
also utilized to
prevent the formation of a weld bead along the channel, thereby ensuring that
the layers
forming the channel are configured to make contact and inhibit two-directional
fluid
flow. In the area of the inlet, however, a weld flow director is partially
absent to
encourage formation of the inlet weld beads.
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[08] A side effect of bonding the valve layer to the second element is that a
corresponding
weld may also be formed between the first valve layer and the first substrate
layer. To
inhibit the formation of this weld, a blocking material may be applied to a
portion of the
surface of the first valve layer that lies adjacent to the first substrate
layer, or the blocking
material may be applied to a surface of the first substrate layer. In some
embodiments, a
blocking material may also be located between the first valve layer and the
second
element. An example of a blocking material that may be positioned between the
valve
layers includes a polytetrafluoroethylene coating or layer.
[09] The method discussed above may be utilized to form a variety of valve
structures from
multiple polymer layers. To provide examples of the various valve structures
and
methods for manufacturing the valve structures, three embodiments are
disclosed. In a
first embodiment of the present invention, four polymer layers are utilized
and the second
element is formed' of a second valve layer and a second substrate layer, the
channel being
formed between the first and second valve layers. In a second embodiment of
the present
invention, three polymer layers are utilized and the second element is formed
of a second
substrate layer, the channel being formed between the first valve layer and
the second
substrate layer. One difference between the first and second embodiments is,
therefore,
the absence of the second valve layer in the second embodiment. In a third
embodiment
of the present invention, the channel welds are joined in the area of the
outlet and an
outlet aperture is formed through one of the valve layers. Fluid may then exit
the valve
of the third embodiment by passing through the outlet aperture. In a manner
that is
similar to the first and second embodiments, the third embodiment may be
constructed
from either three or four polymer layers.
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According to one aspect of the present invention, there is provided a method
of
manufacturing a valve from a plurality of flexible polymer layers, the method
comprising steps of: constructing a first sub-assembly by forming a first
substrate
weld between a first valve layer and a first substrate layer, said first valve
layer
having an inlet portion and an outlet portion; aligning said first sub-
assembly with
a second element such that said first valve layer is positioned between said
first
substrate layer and said second element; and bonding said first valve layer
with
said second element by forming a pair of spaced channel welds between said
first
valve layer and said second element, said channel welds defining a channel
located between said first valve layer and said second element and between
said
channel welds, said channel having an inlet adjacent to said inlet portion and
an
outlet adjacent to said outlet portion.
According to another aspect of the present invention, there is provided a
method
of manufacturing a valve from a plurality of flexible polymer layers,
including a first
valve layer, a first substrate layer, a second valve layer, and a second
substrate,
layer, method comprising the steps of: constructing a first sub-assembly by
forming a first substrate weld between said first valve layer and said first
substrate
layer, said first valve layer having a first inlet portion and first outlet
portion;
constructing a second sub-assembly by forming a second substrate weld between
said second valve layer and said second substrate layer, said second valve
layer
having a second inlet portion and a second outlet portion; aligning said first
sub-
assembly with said second sub-assembly such that said first valve layer is
overlaying and adjacent to said second valve layer and said substrate layers
encompass said valve layers; and bonding said first valve layer with said
second
valve layer by forming a pair of spaced channel welds between said valve
layers,
said channel welds defining a channel located between said valve layers and
between said channel welds, said channel having an inlet adjacent to.said
inlet
portions and an opposite outlet adjacent to said outlet portions.
According to still another aspect of the present invention, there is provided
a
method of manufacturing a valve from a plurality of flexible polymer layers,
including a first valve layer, a first substrate layer, a second valve layer,
and a
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second substrate layer, the method comprising steps of: constructing a first
sub-
assembly by forming a first substrate weld between said first valve layer and
said
first substrate layer, said first valve layer having a first inlet end and an
opposite'
first outlet end; constructing a second sub-assembly by forming a second
substrate weld between said second valve layer and said second substrate
layer,
said second valve Iayer having a second inlet end and an opposite second
outlet
end; aligning said first sub-assembly with said second sub-assembly such that
said first valve layer is overlaying and adjacent to said second valve layer
and said
substrate layers encompass said valve layers; and bonding said first valve
layer
with said second valve layer by forming a pair of shaped channel welds between
said valve layers and forming a pair of inlet weld beads, said channel welds
defining a channel, located between said valve layers and between said channel
welds, said channel having an inlet adjacent to said inlet ends and an
opposite
outlet adjacent to said outlet ends, said inlet weld beads being located
within said
inlet to place said inlet in an open configuration.
According to yet another aspect of the present invention, there is provided a
method of manufacturing a valve from a plurality of flexible polymer layers,
including a first valve layer, a first substrate layer, a second valve layer,
and a
second substrate layer, the method comprising steps of: constructing a first
sub-
assembly by forming a first substrate weld between said first valve layer and
said
first substrate layer with a first RF die that includes a first weld flow
director to
inhibit formation of weld beads adjacent to said first substrate weld, said
first valve
layer having a first inlet end and an opposite first outlet end; constructing
a second
sub-assembly by forming a second substrate weld between said second valve
layer and said second substrate layer with a second RF die that includes a
second
weld flow director to inhibit formation of weld beads adjacent to said second
substrate weld, said second valve layer having a second inlet end and an
opposite
second outlet end; aligning said first sub-assembly with said second sub-
assembly
such that said first valve layer is overlaying and adjacent to said second
valve
layer and said substrate layers encompass said valve layers; and bonding said
first valve layer with said second valve layer by forming a pair of spaced
channel
welds between said valve layers and forming a pair of inlet weld beads, said
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channel welds and said inlet weld beads being formed by a pair of RF dies
having
a pair of weld flow directors, said channel welds defining a channel located
between said valve layers and between said channel welds, said channel having
an inlet adjacent to said inlet ends and an opposite outlet adjacent to said
outlet
ends, said inlet weld beads being located within said inlet to place said
inlet in an
open configuration.
According to a further aspect of the present invention, there is provided a
valve
comprising: a first valve layer and a second valve layer, each said valve
layer
having an inlet portion and an outlet portion; a pair of spaced channel welds
located between said valve layers, said channel welds bonding said valve
layers
to each other; a channel located between said valve layers and between said
channel welds, said channel having an inlet located adjacent to said inlet
portions
and an outlet located adjacent to said outlet portions; and a pair of weld
beads
located in said inlet and adjacent said channel welds, said weld beads placing
said inlet in an open configuration.
According to yet a further aspect of the present invention, there is provided
a valve
comprising: a first valve layer having a first inlet end and an opposite first
outlet
end, said first valve layer defining an outlet aperture in said first outlet
end; a
second valve layer having a second inlet end and an opposite second outlet
end;
a pair of spaced channel welds located between said valve layers, said channel
welds bonding said valve layers to each other, and said channel welds being
joined at said outlet ends; a channel located between said valve layers and
between said channel welds, said channel having an inlet located adjacent to
said
inlet ends and an outlet, said outlet aperture forming said outlet; and a pair
of weld
beads located in said inlet and adjacent said channel welds, said weld beads
placing said inlet in an open configuration.
According to still a further aspect of the present invention, there is
provided a
method of manufacturing a valve from a plurality of flexible polymer layers,
including a valve layer, a first substrate layer, and a second substrate
layer, the
method comprising steps of: constructing a sub-assembly by forming a substrate
weld between said valve layer and said first substrate layer, said valve layer
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having an inlet portion and an outlet portion; aligning said sub-assembly with
said
second substrate layer such that said valve layer is positioned between said
substrate layers; and bonding said valve layer with said second substrate
layer by
forming a pair of spaced channel welds between said valve layer and said
second
substrate layer, said channel welds defining a channel located between said
valve
layer and said second substrate layer and between said channel welds, said
channel having an inlet adjacent to said inlet portion and an opposite outlet
adjacent to said outlet portion.
According to another aspect of the present invention, there is provided a
method
of manufacturing a valve from a plurality of flexible polymer layers,
including a
valve layer, a first substrate layer, and a second substrate layer, the method
comprising steps of: constructing a sub-assembly by forming a substrate weld
between said valve layer and said first substrate layer, said valve layer
having an
inlet end and an opposite outlet end; aligning said sub-assembly with said
second
substrate layer such that said valve layer is positioned between said
substrate
layers; and bonding said valve layer with said second substrate layer by
forming a
pair of spaced channel welds between said valve layer and said second
substrate
layer and forming a pair of inlet weld beads, said channel welds defining a
channel
located between said valve layer and said second substrate layer and between
said channel welds, said channel having an inlet adjacent to said inlet end
and an
opposite outlet adjacent to said outlet end, said inlet weld beads being
located
within said inlet to place said inlet in an open configuration.
According to yet another aspect of the present invention, there is provided a
valve
comprising: a valve layer having an inlet portion and an outlet portion; a
first
substrate layer and a second substrate layer, said valve layer being
positioned
between said substrate layers; a substrate weld formed between said first
substrate layer and said valve layer, said substrate weld bonding said valve
layer
with said first substrate layer; a pair of spaced channel welds located
between
said valve layer and said second substrate layer, said channel welds bonding
said
valve layer with said second substrate layer; a channel located between said
valve
layer and said second substrate layer and between said channel welds, said
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channel having an inlet located adjacent to said inlet portion and an outlet
located
adjacent to said outlet portion; and a pair of weld beads located in said
inlet and
adjacent said channel welds, said weld beads placing said inlet in an open
configuration.
According to still a further aspect of the present invention, there is
provided a
valve comprising: a valve layer having an inlet end and an opposite outlet
end,
said valve layer defining an outlet aperture in said outlet end; a first
substrate layer
and a second substrate layer, said valve layer being positioned between said
substrate layers; a substrate weld formed between said first substrate layer
and
said valve layer, said substrate weld bonding said valve layer with said first
substrate layer; a pair of spaced channel welds located between said valve
layer
and said second substrate layer, said channel welds bonding said valve layer
with
said second substrate layer, and said channel welds being joined at said
outlet
end; a channel located between said valve layer and said second substrate
layer
and between said channel welds, said channel having an inlet located adjacent
to
said inlet end and an outlet, said outlet aperture forming said outlet; and a
pair of
weld beads located in said inlet and adjacent said channel welds, said weld
beads
placing said inlet in an open configuration.
[10] The advantages and features of novelty characterizing some embodiments
of the present invention are pointed out with particularity in the appended
claims.
To gain an improved understanding of the advantages and features of novelty,
however, reference may be made to the following
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descriptive matter and accompanying drawings that describe and illustrate
various
embodiments and concepts related to the invention.
DESCRIPTION OF THE DRAWINGS
[11] The foregoing Summary of the Invention, as well as the following Detailed
Description
of the Invention, will be better understood when read in conjunction with the
accompanying drawings.
[12] FIG. 1 is a perspective view of a fluid system including a valve in
accordance with the
present invention.
[13] FIG. 2A is a perspective view of a first valve in accordance with a first
embodiment of
the present invention.
[14] FIG. 2B is a first cross-sectional view of the first valve, as defined by
line 2B-2B in
FIG. 2A.
[15] FIG. 2C is a second cross-sectional view of the first valve, as defined
by line 2C-2C in
FIG. 2A.
[16] FIG. 2D is a third cross-sectional view of the first valve, as defined by
line 2D-2D in
FIG. 2A.
[17] FIG. 2E is a fourth cross-sectional view of the first valve, as defined
by line 2E-2E in
FIG. 2A.
[18] FIG. 2F is a fifth cross-sectional view of the first valve, as defined by
line 2F-2F in
FIG. 2A.
[19] FIG. 2G is an enlarged view of a weld bead depicted in FIG. 2D.
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1201 FIG. 3A is a perspective view of a first bonding operation prior to
formation of a
substrate weld in accordance with the first embodiment.
[21] FIG. 3B is a cross-sectional view of the first bonding operation prior to
formation of a
substrate weld, as defined by line 3B-3B in FIG. 3A.
[22] FIG. 3C is a cross-sectional view, as depicted in FIG. 3B, of the first
bonding operation
following formation of the substrate weld.
[23] FIG. 3D is a perspective view of a second bonding operation prior to
formation of
channel welds in accordance with the first embodiment.
[24] FIG. 3E is a cross-sectional view of the second bonding operation prior
to formation of
channel welds, as defined by line 3E-3E in FIG. 3D.
[25] FIG. 3F is a cross-sectional view, as depicted in FIG. 3E, of the second
bonding
operation following formation of the channel welds.
[26] FIG. 3G is a perspective view of the second bonding operation, as
depicted in FIG. 3D,
following formation of the channel welds.
[27] FIG. 4A is a perspective view of a second valve in accordance with a
second embodiment
of the present invention.
[28] FIG. 4B is a first cross-sectional view of the second valve, as defined
by line 4B-4B in
FIG. 4A.
[29] FIG. 4C is a second cross-sectional view of the second valve, as defined
by line 4C-4C in
FIG. 4A.
[30] FIG. 4D is a third cross-sectional view of the second valve, as defined
by line 4D-4D in
FIG. 4A.
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[31] FIG. 4E is a fourth cross-sectional view of the second valve, as defined
by line 4E-4E in
FIG. 4A.
[32] FIG. 4F is a fifth cross-sectional view of the second valve, as defined
by line 4F-4F in
FIG. 4A.
[33] FIG. 4G is an enlarged view of a weld bead depicted in FIG. 4D.
[34] FIG. 5A is a perspective view of a first bonding operation in accordance
with the second
embodiment.
[35] FIG. 5B is a cross-sectional view of the first bonding operation prior to
formation of a
substrate weld, as defined by line 5B-5B in FIG. 5A.
[36] FIG. 5C is a cross-sectional view, as depicted in FIG. 5B, of the first
bonding operation
following formation of the substrate weld.
[37] FIG. 5D is a perspective view of a second bonding operation in accordance
with the
second embodiment.
[38] FIG. 5E is a cross-sectional view of the second bonding operation prior
to formation of
channel welds, as defined by line 5E-5E in FIG. 5D.
[39] FIG. 5F is a cross-sectional view, as depicted in FIG. 5E, of the second
bonding
operation following formation of the channel welds.
[40] FIG. 5G is a perspective view of the second bonding operation, as
depicted in FIG. 5D,
following formation of the channel welds.
[41] FIG. 6A is a perspective view of a third valve in accordance with a third
embodiment of
the present invention.
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[42] FIG. 6B is a first cross-sectional view of the third valve, as defined by
line 6B-6B in
FIG. 6A.
[43] FIG. 6C is a second cross-sectional view of the third valve, as defined
by line 6C-6C in
FIG. 6A.
[44] FIG. 6D is a third cross-sectional view of the third valve, as defined by
line 6D-6D in
FIG. 6A.
[45] FIG. 6E is a fourth cross-sectional view of the third valve, as defined
by line 6E-6E in
FIG. 6A.
[46] FIG. 6F is a fifth cross-sectional view of the third valve, as defined by
line 6F-6F in
FIG. 6A.
[47] FIG. 6G is an enlarged view of a weld bead depicted in FIG. 6D.
[48] FIG. 7A is a perspective view of a fourth valve in accordance with the
third embodiment
of the present invention.
[49] FIG. 7B is a first cross-sectional view of the fourth valve, as defined
by line 7B-7B in
FIG. 7A.
[50] FIG. 7C is a second cross-sectional view of the fourth valve, as defined
by line 7C-7C in
FIG. 7A.
[51] FIG. 7D is a third cross-sectional view of the fourth valve, as defined
by line 7D-7D in
FIG. 7A.
[52] FIG. 7E is a fourth cross-sectional view of the fourth valve, as defined
by line 7E-7E in
FIG. 7A.
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[53] FIG. 7F is a fifth cross-sectional view of the fourth valve, as defined
by line 7F-7F in
FIG. 7A.
[54] FIG. 7G is an enlarged view of a weld bead depicted in FIG. 7D.
[55] FIG. 8A is a perspective view of a first bonding operation in accordance
with the third
embodiment.
[56] FIG. 8B is a cross-sectional view of the first bonding operation prior to
formation of a
substrate weld, as defined by line 8B-8B in FIG. 8A.
[57] FIG. 8C is a cross-sectional view, as depicted in FIG. 8B, of the first
bonding operation
following formation of the substrate weld.
[58] FIG. 8D is a perspective view of a second bonding operation in accordance
with the third
embodiment.
[59] FIG. 8E is a cross-sectional view of the second bonding operation prior
to formation of
channel welds, as defined by line 8E-8E in FIG. 8D.
[60] FIG. 8F is a cross-sectional view, as depicted in FIG. 8E, of the second
bonding
operation following formation of the channel welds.
[61] FIG. 8G is a perspective view of the second bonding operation, as
depicted in FIG. 8D,
following formation of the channel welds.
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DETAILED DESCRIPTION OF THE INVENTION
Introduction
[62] The following discussion and the appended figures disclose valves and
various methods
for manufacturing the valves in accordance with the present invention. The
discussion
and figures relate, more particularly, to valves that limit, check, or
otherwise direct fluid
flow within fluid systems and methods for manufacturing the valves. The
valves, as
disclosed, are particularly suited for use with footwear fluid systems and
other types of
athletic equipment. The concepts presented in the following discussion and
figures,
however, may also have applications in the medical, automotive, and aerospace
industries, for example. Accordingly, the present invention is intended to
encompass
valves and methods for manufacturing the valves that are suitable for a wide
range of
products in diverse areas of manufacture.
[63] An exemplar fluid system 10 is depicted in FIG. 1 and includes a pump
chamber 20, a
conduit 30, a valve 40, and a pressure chamber 50. Conduit 30 is configured to
place
pump chamber 20 and pressure chamber 50 in fluid communication. Valve 40 is
located
within conduit 30 and is configured to regulate fluid flow through conduit 30,
thereby
regulating fluid transfer between pump chamber 20 and pressure chamber 50. In
general,
the pressure of a fluid contained within pump chamber 20 rises as pump chamber
20 is
compressed. When the pressure of the fluid within pump chamber 20 exceeds the
pressure of the fluid in pressure chamber 50 plus a differential pressure that
represents an
opening pressure of valve 40, a portion of the fluid within pump chamber 20 is
transferred to pressure chamber 50 by passing through conduit 30 and valve 40.
An inlet
22 provides pump chamber 20 with access to fluid located outside system 10,
thereby
permitting the fluid within pump chamber 20 to be replenished following a
transfer of
fluid to pressure chamber 50.
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164] Conduit 30 may be formed from two layers of polymeric material having
edges that are
bonded together by a peripheral bond 60, thereby forming a passage between the
two
layers. The components forming valve 40 may, therefore, be located between the
layers
forming conduit 30 prior to the formation of peripheral bond 60. Other
components of
fluid system 10, including pump chamber 20 and pressure chamber 50 may be
formed
integral with conduit 30 or separate from conduit 30 and subsequently
attached.
[65] Valve 40 may be a one-directional valve, also referred to as a check
valve, that permits
the fluid to flow from pump chamber 20 to pressure chamber 50, but prevents,
or checks,
fluid flow in the opposite direction. The following discussion discloses a
plurality of
valves 100, 200, and 300, and methods for manufacturing valves 100, 200, and
300, that
are suitable replacements for valve 40. Valves 100, 200, and 300 are also
suitable for use
in other portions of fluid system 10. For example, one of valves 100, 200, or
300 may be
located within inlet 22 to prevent fluid from exiting pump chamber 20 through
inlet 22.
Furthermore, valves 100, 200, and 300 may be utilized as relief valves that
permit the
fluid to exit the fluid system only after a predetermined pressure
differential is achieved
within a specific portion of the fluid system
[66] In a first embodiment of the present invention, a valve 100 and a method
for
manufacturing valve 100 integral with portions of a fluid system are
disclosed. Valve
100 may also be- manufactured separate from the fluid system and subsequently
incorporated into the fluid system. In a second embodiment of the present
invention, a
valve 200 and a method for manufacturing valve 200 integral with portions of a
fluid
system are disclosed. The present invention also discloses a third embodiment,
a valve
300, with an alternate outlet geometry that includes an aperture formed in one
of the
valve layers.
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[67] Fluid system 10 is intended to provide an example of a fluid system
suitable
for incorporating the valves of the present invention. A plurality of other
fluid
systems having varying degrees of complexity are also intended to fall within
the
scope of the present invention. The specific fluid system configuration may be
selected by one skilled in the art depending upon the particular requirements
for
which the fluid system is being utilized.
First Embodiment
[68] The components and function of a valve 100, depicted in FIGS. 2A through
2G, will now be discussed in greater detail. Valve 100 includes a first valve
layer
110a and a second valve layer 110b that are positioned between a first
substrate
layer 120a and a second substrate layer 120b. With respect to fluid system 10,
substrate layers 120a and 120b are analogous to the two polymer layers that
form
pump chamber 20, conduit 30, or pressure chamber 50, for example. One skilled
in the art will recognize, however, that substrate layers 120a and 120b may
also
be the materials that form other types of fluid system components.
[69] First valve layer 110a and second valve layer 110b are bonded together
along opposite sides to form two channel welds 130 and define a channel 140
positioned between valve layers 110a and 110b and between channel welds 130.
Channel 140 includes an inlet 142 and an outlet 144. Inlet 142 is biased in
the
open position by two inlet weld beads 146 formed of polymer material that
collects
in inlet 142 and adjacent to channel welds 130 during the bonding of first
valve
layer 110a and second valve layer 110b. Outlet 144 is located opposite inlet
142
and may be formed of unbonded portions of valve layers 110a and 110b. Each
valve layer 110a or 110b includes an outer surface 112a or 11 2b and an
opposite
inner surface 114. With regard to valve layer 110a, an outer surface 112a lies
adjacent to substrate layer 120a and an inner surface 114a that lies adjacent
to
valve layer 110b. Similarly, valve layer 110b includes an outer surface 112b
that
lies adjacent to substrate layer 120b and an opposite inner surface 114b that
lies
adjacent to valve layer 110a.
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[70] Valve 100 also includes two substrate welds 150 that attach valve layers
110a and 110b to substrate layers 120a and 120b. More specifically, substrate
welds 150 attach valve layer 110a to substrate layer 120a and attach valve
layer
110b to substrate layer 120b. As depicted in FIGS. 2A to 2D, substrate welds
150
are located adjacent to inlet 142. Substrate welds 150 may also be positioned
adjacent to other portions of valve 100.
[71] In operation, valve 100 permits fluid flow through channel 140 and in the
direction from inlet 142 to outlet 144. Valve 100, however, significantly
limits fluid
flow in the opposite direction. As noted, inlet weld beads 146 bias inlet 142
in the
open position. This configuration ensures that the fluid in the fluid system
may
enter at least the portion of channel 140 formed by inlet 142. The primary
factor
that determines whether the fluid may pass through valve 100 is the relative
difference in pressure between the fluid in inlet 142 and the fluid at outlet
144.
When the pressure of the fluid in inlet 142 exceeds the pressure of the fluid
at
outlet 144 plus an opening pressure of valve 100, the force that the fluid in
inlet 142 exerts on inner surfaces 114 of valve layers 110a and 110b is
sufficient
to overcome the force that the fluid at outlet 144 exerts on outer surfaces
112a
and 112b, thereby permitting valve layers 110a and 110b to separate. When
valve layers 110a and 110b separate, fluid may pass through channel 140. When
the pressure of the fluid in inlet 142 is less than the pressure of the fluid
at
outlet 144, however, the force that the fluid in inlet 142 exerts on inner
surfaces 114 of valve layers 110a and 110b is not sufficient to overcome the
force
that the fluid at outlet 142 exerts on outer surfaces 112a and 112b, thereby
preventing valve layers 110a and 110b from separating. When valve layers 110a
and 110b are not separated, channel 140 is effectively closed to fluid
transfer.
[72] Outlet 144 assists in preventing the passage of fluid through valve 100
by
ensuring that valve layers 110a and 110b make a hermetic contact. Note that
channel welds 130, may extend less than the entire length of valve layers 110a
and 110b. Accordingly, outlet 144 may include unbonded portions of valve
layers
110a and 110b. The lack of bonds at outlet 144 permits unobstructed closure at
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outlet 144, thereby providing the hermetic contact between valve layers 110a
and
110b that prevents fluid from passing between valve layers 110a and 110b.
Inner
surfaces 114 may include a smooth, cohesive surface that facilitates closure
of
valve 100. Accordingly, the characteristics of inner surfaces 114 may also
contribute to the hermetic contact and facilitate one-directional fluid flow
through
valve 100.
[73] The materials forming valve layers 110a and 110b and substrate layers
120a and 120b should possess several characteristics. First, the materials
should
permit welds 130 and 150 to securely form between the various material layers
using standard techniques, such as thermal contact, RF energy, laser, and
infrared welding. Second, the materials should also be substantially
impermeable
to fluids, such as air. Third, the materials should possess sufficient
flexibility to
permit valve 100 to operate as described above. Fourth, the materials should
possess a durability that permits valve 100 to operate through numerous
cycles.
Fifth, the materials may be chosen to resist hydrolysis, or chemical breakdown
due to the presence of water, if water or water vapor may be present around
valve
100. Based upon these considerations, suitable materials include thermoplastic
polyurethane, urethane, polyvinyl chloride, and polyethylene. When valve 100
is
formed of thermoplastic polyurethane, a suitable thickness for valve layers 11
Oa
and 11 Ob is 0.018 inches, but may range from 0.004 inches to 0.035 inches,
for
example. Similarly, a suitable thickness for substrate layers 120a and 120b is
0.030 inches, but may range from 0.015 inches to 0.050 inches, for example.
The
thickness of valve layers 11 Oa and 11 Ob and the thickness of substrate
layers
120a and 120b may depart from the ranges listed above, however, depending
upon the specific application for valve 100, the materials and manufacturing
methods utilized, and the properties that valve 100 is intended to impart to
the
fluid system.
[74] A benefit to locating substrate welds 150 adjacent to inlet 142 lies in
the
relatively large area of outer surfaces 112a and 112b that are exposed to the
fluid
at outlet 144. As noted above, when the pressure of the fluid in inlet 142 is
less
than the pressure of the fluid at outlet 144, the force that the fluid in
inlet 142
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exerts on inner surface 114 of valve layers 110a and 110b is not sufficient to
overcome the force that the fluid at outlet 144 exerts on outer surfaces 1 12a
and
112b, thereby preventing valve layers 110a and 110b from separating and
preventing the flow of fluid through valve 100. By configuring the position of
valve
layers 110a and 110b such that a relatively large area of outer surfaces 11 2a
and
112b are exposed to the fluid at outlet 144, the area of contact between inner
surfaces 114 increases proportionally. The primary mechanism that prevents
fluid
from passing through valve 100 is the hermetic contact properties of inner
surfaces 114. Accordingly, increased efficiency is achieved by having a
relatively
large portion of outer surfaces 112a and 112b exposed to the fluid at outlet
144.
[75] A method of manufacturing valve 100 integral with substrate layers 120a
and 120b will now be discussed in relation to FIGS. 3A through 3G. One
skilled'in
the art will recognize that valve 100 may also be manufactured separate from
substrate layers 120a and 120b, and subsequently incorporated into a fluid
system, by omitting steps of the method that involve substrate layers 120a and
120b. In general, the method involves two bonding operations. The first
bonding
operation, depicted in FIGS. 3A-3C, forms a first sub-assembly and a second
sub-
assembly that each includes one substrate layer 120a or 120b and one valve
layer
110a or 110b. More specifically, the first bonding operation forms the first
sub-
assembly by bonding a portion of valve layer 110a to substrate layer 120a to
form
substrate weld 150a. The first bonding operation also forms a second sub-
assembly through a similar operation that includes bonding a portion of valve
layer
110b to substrate layer 120b to form substrate weld 150b. In the second
bonding
operation, depicted.in FIGS. 3D-3F, the sub-assemblies are aligned such that
valve layers 110a and 110b make contact and valve layers 110a and 110b are
positioned between substrate layers 120a and 120b. Channel welds 130 and inlet
weld beads 146 are then formed, thereby completing the manufacture of valve
100. As described in greater detail below, a blocking material may be applied
to
outer surfaces 112a and 112b of valve layers 110a and 110b to prevent
additional
bonds from forming between valve layers 110a and 110b and substrate layers
120a and 120b during the second bonding, operation. Alternately, the blocking
material may be applied to the surfaces of substrate layers 120a and 120b, or
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blocking material may be an additional element of material positioned between
valve layers 11 Oa and 11 Ob and substrate layers 120a and 120b. The blocking
material is not required, however, to manufacture valve 100.
[76] Before performing the first bonding operation, valve layers 11 Oa and
11Ob'
are individually formed. Valve layers 110a and 110b are depicted as having a
rectangular geometry, but may have a plurality of alternate geometries that
are
also suitable for forming valve 100, including square, round, trapezoidal, or
a non-
regular geometry. One consideration regarding the geometry of valve layers 11
Oa
and 11 Ob is the resulting length of channel 140. A channel 140 with a
relatively,
long length may possess a greater opening pressure or lesser flow rate, for
example, than a channel 140 with a relatively short length. Similarly, an
outlet 144
with unbonded portions of valve layers 11 Oa and11Ob that have a relatively
large
surface area may seal more effectively than unbonded portions of valve layers
11 Oa and 11 Ob with a relatively small surface area. Outlet 144 may also be
formed so as to flare outward and around the portion of channel 140 adjacent
to
outlet 144. Accordingly, valve layers 11 Oa and 11Ob may have a variety of
geometries and the specific geometry chosen should depend upon the specific
application for which valve 100 is intended to be utilized and the specific
properties that valve 100 is intended to possess. Examples of properties that
may
be affected by changes in geometry or materials include opening pressure, flow
rate, and back flow rate. With regard to fluid system 10, a valve 100 with a
high
opening pressure may be utilized as a relief valve for pressure chamber 50,
thereby limiting the total pressure in pressure chamber 50. Valve 22 of fluid
.system 10 may also be designed to have a specific opening pressure to limit
the
pressure within both pump chamber 20 and pressure chamber 50.
[77] Once valve layers 110a and 110b are formed, they are positioned with
respect to substrate layers 120a and 120b. Typically, substrate layers 120a
and
120b become one 'or more components of a fluid system. With respect to system
10, for example, substrate layers 120a and 120b could form opposing sides of
conduit 30. Accordingly, valve layers 11Oa and 11Ob should be positioned on
substrate layers 120a and 120b such that inlet 142 will be fluidly-accessible
from
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the side of conduit 30 adjacent to pump chamber 20, and outlet 144 will be
fluidly-
accessible from the side of conduit 30 adjacent to pressure chamber 50,
thereby
placing pump chamber 20 in fluid communication with pressure chamber 50.
1781 Following the positioning of valve layer I l0a with respect to substrate
layer 120a,
substrate weld 150a may be formed. Radio Frequency (RF) welding, which
utilizes RF
energy, is one technique that may be utilized to bond two or more polymer
layers. Other
suitable bonding techniques include thermal contact, laser, and infrared
welding. With
regard to RF welding, an RF die compresses the desired bonding areas and is
activated
such that the areas of contact are irradiated with a specific level of RF
energy for a
predetermined period of time. The RF energy is absorbed by the polymer layers
and the
temperature of the polymer layers rise until portions of the polymer layers
melt. Pressure
applied to the molten polymer layers coupled with subsequent cooling forms a
weld at the
interface between the polymer layers. Typically, a portion of the molten
polymer layers
collects at the edges of the RF die because of the pressure that the RF die
exerts on the
area of contact. The collected polymer then cools to form a weld bead of
formerly
molten polymer material that surrounds the weld area- In applications where a
weld bead
is undesirable, or where a weld bead in certain locations is undesirable, a
weld flow'
director may be added to the RF die. An RF die often includes a surface that
contacts,
places pressure upon, and heats the polymer layers. The weld flow director is
an
extension of the contact surface that does not generate RF energy to form
bonds between
the polymer layers. Instead, the weld flow director distributes the pressure
of the RF die
over a greater area to thereby prevent weld bead formation. Weld flow
directors are often
formed of non-conducting material or a material that is less conducting than
the bonding
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portion of the RF die. Note that the absence of a weld flow director in a
specific location
may be utilized to place a weld bead in the specific location.
1791 With reference to FIG. 3A and 3B, valve layer 110a, substrate layer 120a,
and an RF die
160 are depicted in their relative positions for purposes of the first bonding
operation.
Note that RF die 160 includes a bonding portion 162 and a weld flow director
portion
164. Bonding portion 162 generates the RF energy that forms substrate weld
150a. The
contact surface of bonding portion 162 has a rectangular shape with dimensions
that are
sufficient to bond valve layer I IOa to substrate layer 120a across at least
the width of
inlet 142. Accordingly, bonding portion 162 will heat and bond at least a
portion of the
width of valve layer 1 lOa to substrate layer 120a. Weld flow director portion
164 is
configured to prevent a weld bead from forming adjacent to substrate weld 150a
and
between other portions of valve layer 1 IOa and substrate layer 120a.
Accordingly, weld
flow director portion 164 places additional pressure upon the portion of valve
layer 11Oa
that is intended to remain unbonded to substrate layer 120a. Weld flow
director portion
164 is not, however, configured to prevent the formation of a weld bead around
other
portions of substrate weld 150a. In further embodiments, weld flow director
portion 164
may extend partially or completely around bonding portion 162.
[80] In order to form substrate weld 150a, substrate layer 120a and valve
layer 110a are
positioned and compressed between RF die 160 and another surface, such as a
flat plate
or another die (not depicted). FIG. 3B is a cross-section that depicts the
positions of RF
die 160, substrate layer 120a, and valve layer 11 Oa prior to bonding. FIG. 3C
depicts the
components following the formation of substrate weld 150a. Once substrate weld
150a is
formed, the first sub-assembly is complete.
[81] RF die 160 is depicted as having a stepped configuration between bonding
portion 162
and weld flow director portion 164. As RF energy is emitted from bonding
portion 162,
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the portion of valve layer I IOa in contact with bonding portion 162 and a
corresponding
portion of substrate layer 120a will melt. A portion of the molten polymer
material will
flow out of the bond area, thereby decreasing the overall thickness of layers
I IOa and
120a adjacent to bonding portion 162, as depicted in FIG. 3C. Bonding portion
162 will,
therefore, sink into substrate layer 120a, whereas weld flow director portion
164 will
remain on the plane of substrate layer 120a. One suitable material for valve
layers 11 Oa and 11 Ob
and substrate layers 120a and 120b is thermoplastic polyurethane, as discussed
above. Welds
formed between two layers of thermoplastic polyurethane have sufficient
strength and
durability when the thickness of the weld area is reduced to approximately one-
half of the
total thickness of the layers prior to welding. Accordingly, bonding portion
162 may be
configured, through the stepped configuration discussed above, to sink into
substrate
layer 120a to a depth that is one-half the unwelded thickness of valve layer I
IOa and
substrate layer 120a.
(821 Following the formation of the first subassembly, the second sub-assembly
may be
formed using a similar procedure. The second sub-assembly includes second
substrate
layer 120b and second valve layer 110b that are bonded together to form
substrate weld
150b. The concepts discussed above with regard to formation of the first sub-
assembly
are applicable to the second sub-assembly. Accordingly, the discussion will
now focus
on the remaining portions of the manufacturing process.
(83J The second bonding operation joins the first sub-assembly with the second
sub-assembly
to form valve 100. When incorporating valve 100 into fluid systems that are
more
complex than fluid system 10 further bonding operations may be required to
form other
components of the. fluid system. Valve 100, however, is generally capable of
being
formed by the two bonding operations described herein. One skilled in the art
will be
able to make modifications to the method described herein to integrate valve
100 into
more complex fluid systems.
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[84] With reference to FIG. 3D and 3E, the first and second sub-assemblies are
aligned such that first valve layer 110a is adjacent to second valve layer
110b and
first substrate weld 150a is adjacent to second substrate weld 150b. That is,
valve
layers 110a and 110b are located between substrate layers 120a and 120b and
portions of first valve layer 110a are aligned with corresponding portions of
second
valve layer 110b. Conventional methods may be employed to properly align the
first sub-assembly with the second sub-assembly. For example, locating pins
that
correspond with apertures in the each of the sub-assemblies may be used to
securely and simply align the sub-assemblies during manufacture. Locating pins
may also be utilized in prior portions of the method to form the sub-
assemblies,
thereby ensuring that valve layers 110a and 110b are properly positioned
during
bonding with substrate layers 120a and 120b.
[85] Once the sub-assemblies are properly aligned, an RF die 170a and a
separate RF die 170b are positioned on either side of the aligned sub-
assemblies
and used to form channel welds 130. RF die 170a and 170b may also include
portions that bond substrate layers 120a and 120b to each other to form
conduit
30 in fluid system 10, for example. Note that the second bonding operation may
be completed with a single RF die 170a or 170b. RF dies 170a and 170b each
include a bonding portion 172a or 172b and a weld flow director portion 174a
or
174b. The sections of RF dies 170a and 170b that would be utilized to bond
substrate layers 120a and 120b to each other are omitted from the depiction of
RF
dies 170a and 170b in FIG. 3D. Accordingly, the present discussion will focus
on
the bonding of valve layers 110a and 110b.
[86] In addition to forming channel welds 130, the second bonding operation
inhibits the formation of inlet weld beads 146 adjacent to channel welds 130,
except in the area of inlet 142. Bonding portions 172a and 172b are configured
such that channel welds 130 are formed adjacent to inlet 142. Weld flow
director
portions 174a and 174b are located around the segments of bonding portions
172a and 172b responsible for forming channel welds 130. Accordingly, weld
flow
director portions 174a and 174b are located between the segments of bonding
portions 172a and 172b that form channel welds 130 to prevent the formation of
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weld beads in channel 140. Weld flow director portions 174a and 174b also
extend over the area of outlet 144, but do not extend between the segments of
bonding portions 172a and 172b in the area of inlet 142. This configuration
prompts the formation of inlet weld beads 146 between valve layers 110a and
110b and in inlet 142. As discussed above, inlet weld beads 146 place inlet
142 in
the open position, thereby facilitating the entry of fluid in inlet 142.
[87] Once the sub-assemblies are aligned with RF dies 170a and 170b, the sub-
assemblies are compressed between RF dies 170a and 170b to form channel
welds 130. In addition, excess molten portions of valve layers 110a and 110b
collect adjacent to inlet 142 to form inlet weld beads 146 due to the lack of
weld
flow director portions 174a and 174b in this area. FIG. 3E is a cross-section
that
depicts RF dies 170a and 170b and the subassemblies prior to the second
bonding operation. FIG. 3F depicts the components following the formation of
channel welds 130.
[88] The various areas of RF dies 170a and 170b are depicted as having a
stepped or offset configuration in FIGS. 3D-3F. Whereas RF die 160 includes
two
offset surfaces, one for bonding portion 162 and a second for weld flow
director
.portion 164, RF die 170a or 170b includes three offset surfaces. A careful
review
of the prior discussion and figures will reveal that a first portion of each
channel
weld 130 bonds portions of valve layers 110a and 110b that are utilized to
form a
portion of substrate-welds 150, and a second portion of each channel weld 130
bonds previously unbonded portions of valve layers 110a and 110b. Accordingly,
a first portion of each bonding portion 172a or 172b is configured to fit
within the
indentation formed by substrate welds 150, as depicted in FIGS. 3E and 3F; a
second portion of each bonding portion 172a or 172b is offset from the first
portion
of bonding portion 172 and configured to bond previously unbonded portions of
valve layers 110a and 110b; and weld flow director portion 174a or 174b is
offset
further and configured to compress valve layers 110a and 110b and substrate
layers 120a and 120b to prevent weld bead formation.
[89] In the method described above, substrate welds 150, as formed in the
first
bonding operation, are the solitary attachment sites between valve layers 110a
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and 110b and substrate layers 120a and 120b. In order to prevent additional
bonding between valve layers 11Oa and 11Ob and substrate layers 120a and 120b
during the second bonding operation, a blocking material may be applied to a
portion of outer surfaces 112a and 1 12b before the first bonding operation.
Alternately, the blocking material may be applied to surfaces of substrate
layers
120a and 120b, or the blocking material may be an additional element of
material
positioned between valve layers 11Oa and 11Ob and substrate layers 120a and
120b. Blocking materials prevent intermingling of molten polymers from two
adjacent layers, thereby providing an effective means by which bonding is
inhibited. The blocking material should be applied or positioned adjacent to
the
portion of outer surfaces 112a and 112b where bonding would otherwise occur,
but not to portions of outer surfaces 112a and 112b where bonding is intended
to
occur. For example, the blocking material should not be applied to the area of
outer surfaces 112a and 112b where substrate welds 150 are intended to occur,
thereby facilitating the formation of substrate welds 150 during the first
bonding
operation. An appropriate location for applying a blocking material to outer
surfaces 112a and 112b includes the area opposite the portion of inner
surfaces
114 that are bonded to form channel welds 130, but not adjacent to inlet 142.
Suitable blocking materials include layers or coatings that incorporate
polytetrafluoroethylene, silicone, or mylar, for example. Alternatively, a
blocking
material may be omitted from outer surfaces 11 2a and 11 2b, thereby forming a
bond between substrate layers 120a and 120b and valve layers 11 Oa and 11Ob
during the second bonding operation. For some fluid systems, valve 100
functions
properly when a bond is formed between substrate layers 120a and 120b and
valve layers 11 Oa and 11 Ob.
Second Embodiment
[90] The components and function of a valve 200, depicted in FIGS. 4A through
4G, will now be discussed in greater detail. Valve 200 includes a valve layer
210
that is positioned between a first substrate layer 220a and a second substrate
layer 220b. With respect to fluid system 10,
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substrate layers 220a and 220b are analogous to the two polymer layers that
form pump chamber
20, conduit 30, or pressure chamber 50, for example. One skilled in the art
will recognize,
however, that substrate layers 220a and 220b may also be the materials that
form other types of
fluid system components.
191] Valve layer 210 includes a first surface 212a that lies adjacent to
substrate layer 220a and
a second surface 212b that lies adjacent to substrate layer 220b. A substrate
weld 250 is
formed between first surface 212a and substrate layer 220a to prevent fluid
from flowing
between valve layer 210 and substrate layer 220a. A pair of channel welds 230
are
formed between second surface 212b and substrate layer 220b to define a
channel 240
positioned between channel welds 230 and between valve layer 210 and substrate
layer
220b. Channel 240 includes an inlet 242 and an outlet 244. Inlet 242 is biased
in the
open position by two inlet weld beads 246 formed of polymer material that
collects in
inlet 242 and adjacent to channel welds 230 during the bonding of valve layer
210 and
substrate layer 220b. Outlet 244 is located opposite inlet 242 and may be
formed of
unbonded portions of valve layer 210 and substrate layer 220b. In the first
embodiment,
valve 100 included an inlet 142 and an outlet 144 positioned between valve
layers 110a and 110b
In the second embodiment, however, inlet 242 and outlet 244 are formed between
valve
layer 210 and substrate layer 220b.
1921 In operation, valve 200 permits fluid flow through channel 240 and in the
direction from
inlet 242 to outlet 244. Valve 200, however, significantly limits fluid flow
in the
opposite direction. As noted, inlet weld beads 246 bias inlet 242 in the open
position.
This configuration ensures that the fluid in the fluid system may enter at
least the portion
of channel 240 formed by inlet 242. The primary factor that determines whether
the fluid
may pass through valve 200 is the relative difference in pressure between the
fluid in
inlet 242 and the fluid at outlet 244. When the pressure of the fluid in inlet
242 exceeds
the pressure of the fluid at outlet 244 plus an opening pressure of valve 200,
the force that
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the fluid in inlet 242 exerts on second surface 212b of valve layer 210 is
sufficient to
overcome the force that the fluid at outlet 244 exerts on first surface 212a,
thereby
permitting valve layer 210 to separate from substrate layer 220b. When valve
layer 210
separates from substrate layer 220b, fluid may pass through channel 240. When
the
pressure of the fluid in inlet 242 is less than the pressure of the fluid at
outlet 244,
however, the force that the fluid in inlet 242 exerts on second surface 212b
of valve
layers 210 is not sufficient to overcome the force that the fluid at outlet
242 exerts on first
surfaces 212a, thereby preventing separation of valve layer 210 and substrate
layer 220b.
When valve layer 210 and substrate layer 220b are not separated, channel 240
is
effectively closed to fluid transfer.
1931 Outlet 244 assists in preventing the passage of fluid through valve 200
by ensuring that
valve layer 210 and substrate layer 220b make a hermetic contact. Note that
channel
welds 230 may extend less than the entire length of valve layer 210.
Accordingly, outlet
244 may include unbonded portions of valve layer 210 and substrate layer 220b.
The
lack of bonds at outlet 244 permits unobstructed closure at outlet 244,
thereby providing
the hermetic contact between valve layer 210 and substrate layer 220b that
prevents the
passage of fluid through valve 200. Second surface 212b and the facing surface
of
substrate layer 220b may have a smooth, cohesive surface that facilitates
closure of valve
200. Accordingly, the characteristics of second surface 212b and the surface
of substrate
layer 220b may also contribute to the hermetic contact and facilitate one-
directional fluid
flow through valve 200.
1941 One skilled in the art will recognize that valve 100 and valve 200 differ
in two significant
aspects.. First, valve 200 utilizes only one valve layer 210 rather than two
valve layers
110a and 110b. This configuration has the potential to decrease the overall
thickness of the fluid
system in the area surrounding valve 200. This configuration also decreases
the quantity
of material utilized to form valve 200, thereby decreasing overall cost. -
Second, valve
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200 relies upon substrate layer 220b to form a portion of channel 240, thereby
utilizing
existing fluid system components to form portions of valve 200.
[95] The materials forming valve layer 210 and substrate layers 220a and 220b
should possess
several characteristics. First, the materials should permit welds 230 and 250
to securely form
between the various material layers using standard techniques, such as thermal
contact,
RF energy, laser, and infrared welding. Second, the materials should also be
substantially impenneable to fluids, such as air. Third, the materials should
possess
sufficient flexibility to permit valve 200 to operate as described above.
Fourth, the
materials should possess a durability that permits valve 200 to operate
through
numerous cycles. Fifth, the materials may be chosen to resist hydrolysis, or
chemical
breakdown due to the presence of water, if water or water vapor may be present
around
valve 200. Based on these considerations, suitable materials include
thermoplastic
polyurethane, urethane, polyvinyl chloride, and polyethylene. When valve 200
is formed
of thermoplastic polyurethane, a suitable thickness for valve layer 210 is
0.018 inches,
but may range from 0.004 inches to 0.035 inches, for example. Similarly, a
suitable
thickness for substrate layers 220a and 220b is 0.030 inches, but may range
from 0.015 inches to
0.050 inches. for example. The thickness of valve layer 210 and the thickness
of
substrate layers 220a and 220b may depart from the ranges listed above,
however, depending
upon the specific application for valve 200, the materials and manufacturing
methods utilized,
and the properties that valve 200 is intended to impart to the fluid system.
[96] A benefit to locating substrate welds 250 adjacent to inlet 242, as
depicted in FIGS. 4A
through 4D, lies in the relatively large area of first surface 212a that is
exposed to the fluid at outlet
244. As noted above, when the pressure of the fluid in inlet 242- is less than
the pressure
of the fluid at outlet 244, the force that the fluid in inlet 242 exerts on
second surface
212b of valve layer 210 is not sufficient to overcome the force that the fluid
at outlet 244
exerts on first surface 212a, thereby preventing valve layer 210 from
separating and
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preventing the flow of fluid through valve 200. By configuring the position of
valve
layer 210 such that a relatively large area of first surface 212a is exposed
to the fluid at
outlet 244, the area of contact between second surface 212b and substrate
layer 220b
increases proportionally. One of the primary mechanisms that prevents fluid
from
passing through valve 200 is the hermetic contact properties of second surface
212b and
substrate layer 220b. Accordingly, increased efficiency is achieved by having
a relatively
large portion of first surface 212a exposed to the fluid at outlet 244.
[97] A method of manufacturing valve 200 integral withy substrate layers 220a
and 220b will now
be discussed in relation to FIGS. 5A through 5G. The first bonding operation
forms a first sub-
assembly that includes substrate layer 220a and valve layer 210. More
specifically, the first
bonding operation forms the first sub-assembly by bonding a portion of valve
layer 210
to substrate layer 220a to form substrate weld 250. In the second bonding
operation, the
sub-assemblies are aligned such that valve layer 210 makes contact with the
proper
portion of substrate layer 220b and valve layer 210 is positioned between
substrate layers
220a and 220b. Channel welds 230 and inlet weld beads 246 are then formed,
thereby completing
the manufacture of valve 200. As described in greater detail below, a blocking
material
may be applied to first surface 212a of valve layer 210 to prevent additional
bonds from
forming between valve layer 210 and substrate layer 220a during the second
bonding
operation. Alternately, the blocking material may be applied to a surface of
substrate
layer 220a, or the blocking material may be an additional element of material
positioned
between valve layer 210 and substrate layer 220a. The blocking material is not
required,
however, to manufacture valve 200.
[981 Before performing the first bonding operation, valve layer 210 is formed.
Valve layer
210 is depicted as having a rectangular geometry, but may have a plurality of
alternate
geometries that are also suitable for forming valve 200, including square,
round,
trapezoidal, or a non-regular geometry. One consideration regarding the
geometry of
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valve layers 210 is the resulting length and width of channel 240. A channel
240 with a
relatively long length may impart a greater opening pressure or lesser flow
rate, for
example, than a channel 240 with a relatively short length. A channel 240 with
a
relatively large width may also impart enhanced flow rate and lesser opening
pressure,
for example. Similarly, an outlet 244 with unbonded portions of valve layer
210 that has
a relatively large surface area may seal more effectively than unbonded
portions of valve
layer 210 with a relatively small surface area. Outlet 244 may also be formed
so as to
flare outward and around the portion of channel 240 adjacent to outlet 244.
Accordingly,
valve layer 210 may have a variety of geometries and the specific geometry
chosen
should depend upon the specific application for which valve 200 is intended to
be utilized
and the specific properties that valve 200 is intended to possess. Examples of
properties
that may be affected by changes in geometry or materials include opening
pressure, flow
rate, and back flow rate.
[99] Following, the formation of valve layer 210, it is positioned with
respect to substrate
layers 220a and 220b. Typically, substrate layers 220a and 220b become one or
more
components of a fluid system. With respect to system 10, for example,
substrate layers 220a and
220b could form opposing sides of conduit 30. Accordingly, valve layer 210
should be positioned
on substrate layer 220b such that inlet 242 will be fluidly-accessible from
the side of conduit
30 adjacent to pump chamber 20, and outlet 244 will be fluidly-accessible from
the side
of conduit 30 adjacent to pressure chamber 50, thereby placing pump chamber 20
in fluid
communication with pressure chamber 50.
1100] Once valve layer 210 is positioned with respect to substrate layer 220a,
substrate weld
250 may be formed. With reference to FIGS. 5A and 5B, valve layer 210,
substrate layer
220a, and an RF die 260 are depicted in their relative positions. Note that RF
die 260
includes a bonding portion 262 and a weld flow director portion 264. Bonding
portion
262 generates the RF energy that forms substrate weld 250. The contact surface
of
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bonding portion 262 has a rectangular shape with dimensions that are
sufficient to bond
valve layer 210 to substrate layer 220a across at least the width of inlet
242.
Accordingly, bonding portion 262 will heat and bond at least a portion of the
width of
valve layer 210 to substrate layer 220a. Weld flow director portion 264 is
configured to
prevent a weld bead from forming adjacent to substrate weld 250 and between
other
portions of valve layer 210 and substrate layer 220a. Accordingly, weld flow
director
portion 264 places additional pressure upon the portion of valve layer 210
that is intended
to remain unbonded to substrate layer 220a. In the configuration depicted in
FIG. 5A,
weld flow director portion 264 is not configured to prevent the formation of a
weld bead
around other portions of substrate weld 250. In further embodiments, weld flow
director
portion 264 may extend partially or completely around bonding portion 262. As
with RF
die 160 of the first embodiment, RF die 260 may have a stepped configuration
that
reduces the overall thickness of layers 210 and 220a and 220b in the area of
substrate weld 250.
[101) In order to form substrate weld 250, substrate layer 220a and valve
layer 210 are
positioned and compressed between RF die 260 and another surface, such as a
flat plate
or another die (not depicted). FIG. 5B is a cross-section that depicts the
positions of RF
die 260, substrate layer 220a, and valve layer 210 prior to bonding. FIG. 5C
depicts the
components following the formation of substrate weld 250. Once substrate weld
250 is
formed, the first sub-assembly is complete. Note that the first sub-assembly
is
substantially similar to the first sub-assembly from the first embodiment
[102] The second bonding operation joins the first sub-assembly with the
substrate layer 220b
to form valve 200. When incorporating valve 200 into fluid systems that are
more
complex than fluid system 10 further bonding operations may be required to
form other
components of the fluid system. Valve 200, however, is generally capable of
being
formed by the two bonding operations described herein. One skilled in the art
will be
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able to make modifications to the method described herein to integrate valve
200
into more complex.fluid systems.
[103] With reference to FIGS. 5D and 5E, the first sub-assembly is aligned
such
that valve layer 210 is adjacent to substrate layer 220b. That is, valve layer
210 is
located between substrate layers 220a and 220b. Conventional methods may be
employed to properly align the first sub-assembly with substrate layer 220b.
For
example, locating pins that correspond with apertures in the first sub-
assembly
and substrate layer 220b may be used. Locating pins may also be utilized in
prior
portions of the method to form the first sub-assembly, thereby ensuring that
valve
layer 210 is properly positioned during bonding with substrate layers 220a.
[104] Once the first sub-assembly is properly aligned, an RF die 270a and a
separate RF die 270b are positioned on either side of the aligned sub-
assemblies
and used to form channel welds 230. RF dies 270a and 270b may also include
portions that bond substrate layers 220a and 220b to each other to form a
fluid
system component, such as conduit 30 in fluid system 10, for example. RF dies
270a and 270b each include a bonding portion 272a or 272b and a weld flow
director portion 274a or 274b. The sections of RF dies 270a and 270b that
would
be utilized to bond substrate layers 220a and 220b to each other are omitted
from
the depiction of RF dies 270a and 270b in FIG. 5D. Accordingly, the present
discussion will focus on the bonding of second side 212b of valve layer 210 to
substrate layer 220b.
[105] In addition to forming channel welds 230, the second bonding operation
inhibits the formation of weld beads adjacent to channel welds 230, except in
the
area of inlet 242. Bonding portions 272a and 272b are configured such that
channel welds 130 are formed adjacent to inlet 242. Weld flow director
portions
274a and 274b are located around the segments of bonding portions 272a and
272b responsible for forming channel welds 230. Accordingly, weld flow
director
portions 274a and 274b are located between the segments of bonding portions
272a and 272b that form channel welds 230 to prevent the formation of weld
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beads in channel 240. Weld flow director portions 274a and 274b also extend
over the area of outlet 244, but do not extend between the segments of bonding
portions 272a and 272b in the area of inlet 242. This configuration prompts
the
formation of inlet weld beads 246 in inlet 242 and between valve layer 210 and
substrate layer 220b. As discussed above, inlet weld beads 246 place inlet 242
in
the open position, thereby facilitating the entry of fluid in inlet 242.
[106] Once the first sub-assembly and substrate layer 220b are aligned with RF
dies 270a and 270b, they are compressed between RF dies 270a and 270b to
form channel welds 230. In addition, excess molten portions collect adjacent
to
inlet 242 to form inlet weld beads 246 due to the lack of weld flow director
portions
274a and 274b in this area. FIG. 5E is a cross-section that depicts RF dies
270a
and 270b, the first sub-assembly, and substrate layer 220b prior to the second
bonding operation. FIG. 5F depicts the components following the formation of
channel welds 230. As with RF dies 170a and 170b of the first embodiment, at
least RF die 270a may have a stepped configuration with three offset surfaces.
RF die 270b, however, may only have two offset surfaces, as depicted in
FIGS. 5E and 5F, between bonding portion 272b and weld flow director portion
274b. Alternately, RF die 270b may have a flat surface that does not include
the
highest step depicted in FIGS. 5E and 5F.
[107] In the method described above, substrate weld 250, as formed in the
first
bonding operation, is the solitary attachment site between valve layer 210 and
substrate layer 220a. In order to prevent additional bonding between valve
layer
210 and substrate layers 220a during the second bonding operation, a blocking
material may be applied to a portion of first surface 212a before the first
bonding
operation. The blocking material should be applied or positioned adjacent to
the
portion of first surface 212a where bonding would otherwise occur, but not to
portions of first surface 212 where bonding is intended to occur. For example,
the
blocking material should not be applied to the area of first surface 212a
where
substrate weld 250 is intended to occur, thereby facilitating the formation of
substrate weld 250 during the first bonding operation. An appropriate location
for
applying a blocking material to first surface 212a includes the area opposite
the,
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portion of second surface 212b that is bonded to form channel welds 230, but
not
adjacent to inlet 242. Alternatively, a blocking material may be omitted from
first
surface 212a, thereby forming a bond between substrate layers 220a and 220b
and valve layer 210 during the second bonding operation.
Third Embodiment
[108] The components and function of a valve 300, depicted in FIGS. 6A through
6G, will now be discussed in greater detail. Valve 300 includes a first valve
layer
310a and a second valve layer 310b that are positioned between a first
substrate
layer 320a and a second substrate layer 320b. With respect to fluid system 10,
substrate layers 320a and 320b are analogous to the two polymer layers that
form
pump chamber 20, conduit 30, or pressure chamber 50, for example. One skilled
in the art will recognize, however, that substrate layers 320a and 320b may
also
be the materials that form other types of fluid system components.
[109] First valve layer 310a and second valve layer 310b are bonded together
by
a pair of channel welds 330 that define a channel 340 positioned between valve
layers 310a and 310b and between opposite sides of channel weld 330. Channel
340 includes an inlet 342 and an outlet 344. Inlet 342 is biased in the open
position by two inlet weld beads 346 formed of polymer material that collects
in
inlet 342 and adjacent to channel weld 330 during the bonding of first valve
layer
310a and second valve layer 310b. Unlike valve 100 of the first embodiment,
channel welds 330 are joined in the area of outlet 344 and enclose outlet 344.
Accordingly, an outlet aperture 348 is formed through valve layer 310a. Each
valve layer 310a or 310b includes an outer surface 312a or 312b and an inner
surface 314. With regard to valve layer 310a, for example, outer surface 312a
lies
adjacent to substrate layer 320a and is bonded to substrate layer 320a. Valve
layer 310a also includes an inner surface 314a that lies adjacent to valve
layer
310b. Similarly, valve layer 310b includes an outer surface 312b that lies
adjacent
to substrate layer 320b and an opposite inner surface 314b that lies adjacent
to
inner surface 314a.
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[110] Valve 300 also includes two substrate welds 350 that attach valve layers
310a and 310b to substrate layers 320a and 320b. More specifically, substrate
welds 350 attach valve layer 310a to substrate layer 320a and attach valve
layer
310b to substrate layer 320b. As depicted in FIGS. 6A to 6D, substrate welds
350
are located adjacent to inlet 342. Substrate welds 350 may also be positioned
adjacent to other portions of valve 300.
[111] Valve 300 operates in a manner that is similar to valve 100 of the first
embodiment. Fluid flows through channel 340 and in the direction from inlet
342
to outlet 344. Fluid then exits valve 300 by passing through outlet aperture
348.
Valve 300, however, significantly limits fluid flow in the opposite direction.
As
noted, inlet weld beads 346 bias inlet 342 in the open position. This
configuration
ensures that the fluid in the fluid system may enter at least the portion of
channel
340 formed by inlet 342. As with the prior embodiments, the primary factor
that
determines whether the fluid may pass through valve 300 is the relative
difference
in pressure between the fluid in inlet 342 and the fluid at outlet 344. When
the
pressure of the fluid in inlet 342 exceeds the pressure of the fluid at outlet
344
plus an opening pressure of valve 300, the force that the fluid in inlet 342
exerts,
on inner surfaces 314 of valve layers 310a and 310b is sufficient to overcome
the
force that the fluid at outlet 344 exerts on outer surfaces 312a and 312b,
thereby
permitting valve layers 310a and 310b to separate. When valve layers 310a and
310b separate, fluid may pass through channel 340 and exit valve 300 through
outlet aperture 348. When the pressure of the fluid in inlet 342 is less than
the
pressure of the fluid at outlet 344, however, the force that the fluid in
inlet 342
exerts on inner surfaces 314 of valve layers 310a and 310b is not sufficient
to
overcome the force that the fluid at outlet 342 exerts on outer surfaces 312a
and
312b, thereby preventing valve layers 310a and 310b from separating. When
.valve layers 310a and 310b are not separated, channel 340 is effectively
closed to
fluid transfer.
[112] Outlet 344 assists in preventing the passage of fluid through valve 300
by
ensuring that valve layers 310a and 310b make a hermetic contact. Valve 300 is
structured such that channel weld 330 surrounds outlet aperture 348, but is
also
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spaced away from outlet aperture 348. The spacing ensures that valve layers
310a and 310b may make hermetic contact around outlet aperture 348, thereby
preventing fluid from passing between valve layers 310a and 310b. Inner
surfaces 314 may include a smooth, cohesive surface that facilitates closure
of
valve 300. Accordingly, the characteristics of inner surfaces 314 may also
contribute to the hermetic contact and facilitate one-directional fluid flow
through
valve 300. The considerations discussed in relation to valves 100 and 200 are
also relevant to valve 300. Accordingly, suitable materials for valve layers
310a
and 310b and substrate layers 320a and 320b include thermoplastic
polyurethane,
urethane, polyvinyl chloride, and polyethylene. Based upon the above
discussion,
valve 300 is structurally similar to valve 100, the primary differences
relating to the
geometry of channel welds 330 and outlet 344.
[113] As an alternative structure, depicted in FIGS. 7A through 7G, a similar
valve 400 may be formed from a single valve layer 410 rather than the two
valve
layers 310a and 310b disclosed above. Accordingly, valve layer 410 may be
positioned between two substrate layers 420 and a pair of channel welds 430
are
formed between valve layer 410 and substrate layer 420b to define a channel
440
between valve layer 410 and substrate layer 420b. Channel welds 430 are joined
in the area of an outlet 444 and surround an outlet aperture 448.
Structurally,
therefore, valve 400 is similar to valve 200, the primary difference relating
to they
geometry of channel welds 430 and outlet 444.
[114] One skilled in the relevant art will recognize that the similarities in
structure,
function, and method for manufacture between valves 300 and 400 do not require
a separate discussion regarding valve 400. Consequently, the following
discussion regarding a method for manufacturing will focus primarily upon
valve
300, with an understanding that similar concepts apply generally to valve 400.
[115] A method of manufacturing valve 300 will now be discussed in relation to
FIGS. 8A through 8G. In general, the method involves two bonding operations.
The first bonding operation, depicted in FIGS. 8A-8C, forms a first sub-
assembly
and a second sub-assembly that each include one substrate layer 320a or 320b
and one valve layer 310a or 310b. More specifically, the first bonding
operation
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forms the first sub-assembly by bonding a portion of valve layer 310a to
substrate
layer 320a to form substrate weld 350a with an RF die 360, which includes a
bonding portion 362 and a weld flow director portion 364. The first bonding
operation also forms a second sub-assembly through a similar operation that
includes bonding a portion of valve layer 310b to substrate layer 320b to form
substrate weld 350b. In the second bonding operation, depicted in FIGS. 8D-8G,
the sub-assemblies are aligned such that valve layers 310a and 310b make
contact and valve layers 310a and 310b are positioned between substrate layers
320a and 320b. Channel welds 330 and inlet weld beads 346 are then formed,
thereby completing the manufacture of valve 300. Weld beads 346 may also have
an alternate configuration that extends at least partially down channel 340.
As
described in greater detail below, a blocking material may be applied to outer
surfaces 312a and 312b of valve layers 310a and 310b to prevent additional
bonds from forming between valve layers 310a and 310b and substrate layers
320a and 320b during the second bonding operation. Alternately, the blocking
material may be applied to surfaces of substrate layers 320a and 320b, or the
blocking material may be an additional element of material that is positioned
between valve layers 310a and 310b and substrate layers 320a and 320b.
[116] Before performing the first bonding operation, valve layers 310a and
310b
are individually formed. Valve layers 310a and 310b are depicted as having a
rectangular geometry with a circular portion forming outlet 344, but may have
a
plurality of alternate geometries that are also suitable for forming valve
300,
including square, round, trapezoidal, or a non-regular geometry. In addition,
outlet
aperture 348 is formed in valve layer 310a. Once valve layers 310a and 310b
are
formed, they are positioned with respect to substrate layers 320a and 320b.
Typically, substrate layers 320a and 320b become one or more components of a
fluid system. With. respect to system 10,
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for example, substrate layers 320a and 320b may form opposing sides of conduit
30, for example.
Accordingly, valve layers 310a and 310b would be positioned on substrate
layers 320a and 320b
such that inlet 342 will be fluidly-accessible from the side of conduit 30
adjacent to pump chamber
20, and outlet 344 will be fluidly-accessible from the side of conduit 30
adjacent to pressure
chamber 50, thereby placing pump chamber 20 in fluid communication with
pressure
chamber 50.
11171 Following the positioning of valve layer 310a with respect to substrate
layer 320a,
substrate weld 350a may be formed through RF welding, for example. With
reference to
FIG. 8A and 8B, valve layer 310a, substrate layer 320a, and an RF die 360 are
depicted
in their relative positions for purposes of the first bonding operation. Note
that RF die
360 includes a bonding portion 362 and a weld flow director portion 364.
Bonding
portion 362 generates the RF energy that forms substrate weld 350a_ The
contact surface
of bonding portion 362 has a rectangular shape with a width that corresponds
to the width
of valve layer 310a in the area of inlet 342. Accordingly, bonding portion 362
will heat
and bond the width of valve layer 310a to substrate layer 320a. Weld flow
director
portion 364 is configured to prevent a weld bead from forming adjacent to
substrate weld
350a and between other portions of valve layer 310a and substrate layer 320a.
Accordingly, weld flow director portion 364 places additional pressure upon
the portion
of valve layer 310a that is intended to remain unbonded to substrate layer
320a. Weld
flow director portion 364 is not, however, configured to prevent the formation
of a weld
bead around other portions of substrate weld 350a. In further embodiments,
weld flow
director portion 364 may extend partially or completely around bonding portion
362.
1118] In order to form substrate weld 350a, substrate layer 320a and valve
layer 310a are
positioned and compressed between RF die 360 and another surface, such as a
flat plate
or another die (not depicted). FIG. 8B is a cross-section that depicts the
positions of RF
die 360, substrate layer 320a, and valve layer 310a prior to bonding. FIG. 8C
depicts the
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components following the formation of substrate weld 350a. Once substrate weld
350a is
formed, the first sub-assembly is complete. RF die 360 may have a stepped
configuration, as with RF dies 160 and 260.
[1191 Following the formation of the first subassembly, the second sub-
assembly may be
formed using a similar procedure. The second sub-assembly includes second
substrate
layer 320b and second valve layer'31Ob that are bonded together to form
substrate weld
350b. The concepts discussed above with regard to formation of the first sub-
assembly
are applicable to the second sub-assembly. Accordingly, the discussion will
now focus
on the remaining portions of the manufacturing process.
11201 The second bonding operation joins the first sub-assembly with the
second sub-assembly
to form valve 300. When incorporating valve 300 into fluid systems that are
more
complex than fluid system 10 further bonding operations may be required to
form other
components of the fluid system. Valve 300, however, is generally capable of
being
formed by the two bonding operations described herein. One skilled in the art
will be
able to make modifications to the method described herein to integrate valve
300 into
more complex fluid systems.
[1211 With reference to FIG. 8D and 8E, the first and second sub-assemblies
are aligned such
that first valve layer 310a is adjacent to second valve layer 3106 and first
substrate weld
350a is adjacent to second substrate weld 350b. That is, valve layers 310a and
310b are located
between substrate layers 320a and 320b and portions of first valve layer 31 Oa
are aligned with
corresponding portions of second valve layer 310b. Conventional methods may be
employed to properly align the first sub-assembly with the second sub-
assembly. For
example, locating pins that correspond with apertures in the each of the sub-
assemblies
may be used to securely and simply align the sub-assemblies during
manufacture.
Locating pins may also be utilized in prior portions of the method to form the
sub-
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assemblies, thereby ensuring that valve layers 310a and 310b are properly
positioned during bonding with substrate layers 320a and 320b.
[122] Once the sub-assemblies are properly aligned, an RF die 370a and a
separate RF die 370b are positioned on either side of the aligned sub-
assemblies
and used to form channel welds 330. RF die 370 may also include portions that,
bond substrate layers 320a and 320b to each other for form conduit 30 in fluid
system 10, for example. If, however, valve 300 is utilized as an inlet valve
for a
chamber, then RF die 370 may include portions that form a perimeter bond of
the
chamber. Note that the second bonding operation may be completed with a single
RF die 370, but this arrangement may result in an uneven heating distribution
that
causes non-uniform melting of layers 310a and 310b. RF dies 370 each include a
bonding portion 372a or 372b and a weld flow director portion 374a or 374b.
The
sections of RF dies 370 that would be utilized to bond substrate layers 320a
and
320b to each other-are omitted from the depiction of RF dies 370 in Fig. 8D.
Accordingly, the present discussion will focus on the bonding of valve layers
310a
and 310b.
[123] In addition to forming channel welds 330, the second bonding operation
inhibits the formation of inlet weld beads 346 adjacent to channel welds 330,
except in the area of inlet 342. Bonding portions 372a and 372b are configured
such that channel welds 330 are formed adjacent to inlet 342. Weld flow
director
portions 374a and 374b are located within bonding portions 372a and 372b.
Accordingly, weld flow director portions 374a and 374b are located within the
area
of bonding portions 372a and 372b that form channel welds 330 to prevent the
formation of weld beads in the area of outlet 344. Weld flow director portions
374a and 374b do not extend between the segments of bonding portions 372a
and 372b in the area of inlet 342. This configuration prompts the formation of
inlet
weld beads 346 between valve layers 310a and 310b and in inlet 342. As
discussed above, inlet weld beads 346 place inlet 342 in the open position,
thereby facilitating. the entry of fluid in inlet 342.
[124] The geometry of RF dies 370 differs from the geometries of RF dies 170a
and 170b, and 270a and 270b. In order to join channel welds 330, bonding
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portions 372a and 372b extend around outlet 344 and are joined in the area of
outlet 344. Weld flow director portions 374a and 374b are centered around
outlet
aperture 348 to prevent the formation of weld beads in the area of outlet 348.
[125] Once the sub-assemblies are aligned with RF dies 370, the sub-
assemblies are compressed between RF dies 370 to form channel welds 330. In
addition, excess molten portions of valve layers 310a and 310b collect
adjacent to
inlet 342 to form inlet weld beads 346 due to the lack of weld flow director
portions
374a and 374b in this area. FIG. 8E is a cross-section that depicts RF dies
370
and the sub-assemblies prior to the second bonding operation. FIGS. 8F and 8G
depict the components following the formation of channel welds 330. As with RF
dies 170a and 170b, and 270a and 270b, the various areas of RF dies 370 may
have a stepped or offset configuration. As a side effect of the second bonding
operation, welds may be formed between valve layers 310a and 310b and
substrate layers 320a and 320b unless a blocking material is utilized in these
areas.
[126] One skilled in the art will recognize that valve 300 may also be
manufactured separate from substrate layers 320a and 320b, and subsequently
incorporated into a fluid system, by omitting steps of the method that involve
substrate layers 320a and 320b. Depending upon the final use for valve 300, a
blocking material may be located within inlet 342 to prevent valve layers 310a
and
310b from being bonded to each other when incorporating valve 300 into a fluid
system.
[127] The present invention is disclosed above and in the accompanying
drawings with reference to a variety of embodiments. The purpose served by the
disclosure, however, is to provide an example of the various features and
concepts related to the invention, not to limit the scope of the invention.
One
skilled in the relevant art will recognize that numerous variations and
modifications
may be made to the embodiments described
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WO 2004/027300 PCT/US2003/025856
above without departing from the scope of the present invention, as defined by
the
appended claims.
39
